In recent years, contactless communication using near-field coupling has been proposed for inter-layer signal transmission in a multi-layer substrate using an IC (Integrated Circuit) bare chip, PCB (Printed Circuit Board), or the like. Typically, a TSV (Through Silicon Via) or the like is used for inter-layer communication. However, in order to increase the number of inter-layer transmission pathways, the number of TSVs must also be increased, thus hindering miniaturization of a device in which the multi-layer substrate is provided. On the other hand, by performing contactless communication, installation space is not required for TSVs and the degree of design freedom is increased, thus allowing reduction in surface area of the multi-layer substrate.
Furthermore, in contactless communication digital baseband signals can be transmitted and received without modification, therefore contactless communication has an advantage that mounting of circuits for performing modulation and demodulation is not necessary.